1. Field of the Invention
The present invention relates to a rolled recording medium conveyance device, an image forming apparatus, a rolled recording medium conveyance method, and a computer program product that contains a rolled recording medium conveyance program. Particularly, the present invention relates to a rolled recording medium conveyance device, an image forming apparatus, a rolled recording medium conveyance method, and a computer program product that contains a rolled recording medium conveyance program by which an end edge portion of a rolled recording medium such as roll paper is properly discharged from a conveyance path.
2. Description of the Related Art
An image forming apparatus which forms an image on a wide sheet of paper with an AO width or the like generally uses roll paper to form an image thereon, where the roll paper is provided in the form of a long piece of paper rolled around a core pipe.
The image forming apparatus using such roll paper performs printing by pulling paper out of the roll paper according to the length of an image to be printed, pulls the roll paper out to a cutter position according to the length of the printed image, and cuts the paper being pulled out.
Having cut the roll paper, the image forming apparatus using the roll paper discharges the paper on which the image is formed to a paper discharge tray, conveys the roll paper in a reverse conveyance direction (a direction opposite to a forward conveyance direction) by rolling the roll paper back around the core pipe to a predetermined standby position, and stands by for the next image formation.
The roll paper includes the one with an end edge thereof adhered to the core pipe and the one with the end edge simply rolled around the core pipe without being adhered thereto.
When the roll paper has a free end edge which comes off of the core pipe, the image forming apparatus using such roll paper generally employs two methods to detect the end edge of the roll paper, or a roll end, in the related art. One detection method is a sensor method in which a detection result by a roll paper detection sensor changes from a result indicating there is paper to a result indicating there is no paper, the roll paper detection sensor detecting the presence of the roll paper disposed on a conveyance path provided for the roll paper. Another detection method is an encoder method in which a detection result by an encoder shows a rapid increase (idling), the encoder detecting rotation of a conveyance motor which conveys the roll paper.
Now, there has been proposed in the related art a recording device which uses a recording head to perform recording on roll paper discharged from a roll paper shaft and includes a near-end edge detection unit which detects that the roll paper has come close the end edge thereof and a roll paper drive unit which drives the roll paper (refer to Japanese Laid-open Patent Publication No. 2009-269713). This recording device determines whether or not the end edge of the roll paper is fixed to the roll paper shaft and thus cannot be conveyed, when the near-end edge detection unit has detected the vicinity of the end edge of the roll paper, by changing a driving condition of the roll paper drive unit.
That is, in this technology in the related art, upon detecting the vicinity of the end edge of the roll paper and detecting whether or not the end edge of the roll paper is fixed to the core pipe, and in case the end edge is not fixed, this technology is aimed to not waste but use the end edge portion of the roll paper.
However, in the aforementioned technology in the related art, even when the roll end is detected, there has been a possible problem that a fragmentary piece of the roll paper is left on the conveyance path when the end edge of the roll paper is weakly adhered to the core pipe, thereby requiring a great amount of work to take out the piece of paper.
In other words, the roll paper is sometimes incompletely adhered to the core pipe so that the end edge of the roll paper is peeled dividedly from the core pipe (falls off in a fragment). There is a possibility, for such roll paper with the end edge being easily peeled dividedly from the core pipe, that the end edge of the roll paper comes off of the core pipe while the roll paper is rolled back near the end edge thereof. There has been a problem that, when the end edge of the roll paper comes off of the core pipe while it is rolled back, a fallen fragment of the peeled end edge portion of the roll paper is left in the conveyance path so that the usability of a device is decreased due to work for removing of the fragment.
Now, in view of the above-mentioned problems in the aforementioned technology, there is needed to discharge the fallen end edge portion of a rolled recording medium from the conveyance path.